About this replacement
Dell X15 R2 — 11.4V Li-ion Replacement Battery (DWVRR / NR6MH)
This is an 11.4V, 7250mAh (82.65Wh) Li-ion battery for the Dell XPS 15 R2 notebook. It fits the WNR2X15CTO40S, NAHMX15R2_H90E, NAWX15R210SC, WNR2X15FTROH, and over 49 additional X15 R2 configurations. The OEM equivalents are DWVRR and NR6MH.
- X15 R2 platform compatibility: All listed X15 R2 variants share the same 11.4V three-cell battery rail, connector pinout, and BMS handshake protocol. The DWVRR and NR6MH part numbers are interchangeable across these configurations — Dell used both codes across production runs of the same chassis.
- Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on an X15 R2 unit. The BMS communicated cleanly with the EC, charge current tapered correctly at the 4.35V per-cell ceiling, and no protection trips occurred during load testing under sustained CPU and GPU draw.
- First-cycle calibration on the X15 R2: After installing, run one full discharge down to the hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning the system logs after every cell swap. Skip this step and Windows will report degraded health even on a fresh cell.
BIOS reporting poor battery health after replacement on the X15 R2
The X15 R2 EC reads cycle count, state-of-health, and rated Wh from the battery's EEPROM on every boot. A new cell ships with factory EEPROM values that don't match the learned data the old cell built up — so the BIOS flags it as degraded before a single charge cycle has run. This is not a fault with the replacement cell. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100%, and the BIOS learn cycle will rewrite its baseline against the new cell's actual chemistry. After two to three cycles the health percentage normalises.
X15 R2 shutting down suddenly while the OS still shows 20–30% remaining
This happens when the cell can no longer sustain voltage under the combined draw of the 45W CPU, discrete GPU, and 15-inch display — the voltage collapses below the BMS cutoff threshold before the fuel gauge reaches zero. The fuel gauge IC is calibrated against an older cell's discharge curve, so the percentage readout lags behind actual cell state. The fix is the same calibration cycle: discharge fully to hibernate cutoff, then charge straight to 100% without interruption. After two full cycles the fuel gauge IC re-maps its curve to the new cell and the shutdown-at-30% behaviour stops.